Microwave Assisted Combustion technique was employed to prepare higly stable niobium pentoxide - Nb2O5-nanoparticles using ammonium niobium oxalate as precursor, ammonium nitrate as oxidant and urea as fuel. The synthesized sample has showed good results for catalytic processes and its morphological and crystalline characterizations have been performed using gas adsorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy and X-ray diffraction. This routine is quite promising for massive production of high quality crystalline Nb2O5 nanoparticle without further calcination or heat treatment for photocatalytical processes.